GPS rival Xona plans 258 low-orbit satellites with 100× stronger signal

Xona Space Systems, a California-based startup, is planning to challenge GPS's dominance with a constellation of 258 satellites called Pulsar, operating in low-Earth orbit where they can deliver signals 100 times stronger than existing global navigation satellite systems. The first six production satellites are scheduled to launch in October 2026, with early service beginning in 2027. The company has already launched Pulsar-0 aboard a SpaceX Falcon 9 rocket rideshare mission on July 1, 2025, and has begun demonstrating the system's advantages through live-sky testing.

The core appeal of Xona's approach is that stronger signals enable location services where GPS fails. Navigators, city planners, and app developers have long struggled with GPS's inability to penetrate dense urban buildings, thick foliage, and indoor environments. More recently, GPS jamming has emerged as a widespread problem affecting commercial aviation, maritime shipping, and smartphone applications. Pulsar's stronger signal can reduce a jammer's effective area by 95 percent, according to Xona's live-sky jamming tests across multiple countries. The company has also built anti-spoof authentication directly into its signals, allowing receivers to verify that a signal genuinely comes from Xona's satellite rather than a spoofed source. Testing of Pulsar-0 improved the satellite's native positioning accuracy from an initial 4.2-centimeter ranging error to 1.5-centimeter accuracy through software updates. Adrien Perkins, co-founder and VP of engineering, explained to Ars: "Our higher power allows you to get into those jamming environments a lot further than you would with GPS by itself."

Xona's initial market targets organizations with exceptional dependence on reliable positioning and timing. The company has already signed several precision-timing customers in financial markets, telecommunications, data centers, and transportation systems. According to Zak Kassas, director of the Autonomous Systems Perception, Intelligence, and Navigation Laboratory at The Ohio State University, early adopters will likely be "defense and national security users and government agencies responsible for resilience." The company expects to provide timing signals accurate to within 10 nanoseconds—far more precise than GPS, which uses expensive atomic clocks aboard satellites. Pulsar satellites will rely on software-based timing solutions, a much cheaper alternative. Centimeter-level positioning will become available once four Pulsar satellites are visible from a given region, an achievement Xona expects to reach for priority areas before the full constellation launches. Timing services requiring at least one satellite in regular view will arrive once roughly 16 satellites are in orbit.

Xona's manufacturing strategy combines external partnerships with aggressive internal scaling. The company has contracted with Aerospacelab, a Belgian satellite manufacturer, to build some of the first satellites. However, Xona is developing its own in-house satellite bus design and manufacturing capability at its Burlingame, California factory to produce most of the 258 planned Pulsar satellites. The company hired its first satellite development engineer roughly a year before speaking with Ars and has since brought on Tim Graham, an engineer who spent a decade at SpaceX managing avionics on the Raptor engines that power Starship. Graham is now leading satellite development across hardware, software, and propulsion. CEO Brian Manning, a co-founder, previously worked at SpaceX redesigning components of the Falcon 9 rocket's thrust structure. When Ars visited Xona in June, two in-house satellite buses scheduled for the October 2026 launch were undergoing vibration testing to simulate the stress of rocket launch and identify design weaknesses before orbital deployment. Graham explained his engineering philosophy, learned at SpaceX: "A test that doesn't break something or show you something new is not super valuable. Let's just try it and see what works, see what breaks, and then make it stronger."

Xona's revival of low-Earth orbit navigation echoes the history of the Transit system, the US Navy's first satellite navigation network, which launched operationally in 1964. Transit relied on measuring Doppler shift—the change in radio signal frequency as a satellite passed overhead—to calculate both the satellite's position and a receiver's location on Earth. The idea emerged from Johns Hopkins University physicists who developed the technique while studying the Soviet Union's Sputnik-1. Transit's constellation of just 36 operational satellites could only provide location fixes every hour or two when a satellite passed over the horizon, which sufficed for submarines calculating missile launch coordinates but felt inadequate by modern standards. GPS replaced Transit by using medium-Earth orbit satellites, which required fewer spacecraft to achieve near-instantaneous global coverage but operated at higher altitude with weaker signals. According to Kassas, delivering comparable performance from low-Earth orbit requires approximately 10 times more satellites. Until recently, the scale and cost of such a constellation seemed prohibitive. SpaceX's advent of lower-cost rocket launches, demonstrated by the Starlink megaconstellation of thousands of satellites, has made deploying hundreds of dedicated navigation satellites economically feasible. Xona and other competitors are now exploiting this shift to bring enhanced PNT services within reach of organizations that depend critically on resilience, accuracy, and resistance to jamming.

Xona's revival of low-Earth orbit navigation represents a return to principles explored by the Transit system, the US Navy's first satellite navigation network deployed in the 1960s. Transit used Doppler shift measurements from satellites in low orbit to locate submarines but could only provide fixes every hour or two because its 36-satellite constellation was too sparse. GPS replaced it by using medium-Earth orbit satellites, which required fewer spacecraft but operated at higher altitude with weaker signals. The fundamental trade-off—more satellites in lower orbit for stronger signals versus fewer satellites in higher orbit for broader coverage—now favors the low-orbit approach because manufacturing and launch costs have dropped dramatically, driven largely by SpaceX's reusable rockets.

Xona's competitive edge rests on two technical breakthroughs: signal strength and authentication. The 100 times stronger signal compared to GPS can penetrate buildings and reduce jamming vulnerability—a critical advantage as GPS disruption becomes endemic to aviation, shipping, and consumer apps. The company has already demonstrated this in live-sky jamming tests that reduced effective jammer range by 95 percent. Xona is also incorporating anti-spoof watermarks into its signals, addressing a security gap in traditional GPS. Early tests improved Pulsar-0's ranging accuracy from 4.2 centimeters to 1.5 centimeters, suggesting the full constellation could deliver centimeter-level geolocation.

The company's hiring strategy reveals confidence in execution: Tim Graham, formerly the engineering manager for SpaceX Starship's Raptor engines, joined to lead satellite development; co-founder CEO Brian Manning previously redesigned Falcon 9 thrust structures at SpaceX. This talent migration signals that low-cost constellation deployment, once a research problem, is now an engineering discipline that proven engineers are willing to bet their careers on. The October 2026 target for six production satellites is aggressive but grounded—the company has already completed two satellite buses and is conducting vibration testing, a standard SpaceX methodology that Graham brought with him.